Tyrosol, a phenylethanoid and a derivative of phenethyl alcohol, possesses various biological properties, such as anti-oxidative and cardioprotective activity. Olive oil is the principal source of tyrosol in the human diet. However, so far the anti-cancer activity of tyrosol has not yet been well defined. This study therefore undertakes to examine the cytotoxic activity and the mechanism of cell death exhibited by tyrosol in KB human oral cancer cells. Treatment of KB cells with tyrosol induced the cell growth inhibition in a concentration- and a time-dependent manner. Furthermore, the treatment of tyrosol induced nuclear condensation and fragmentation of KB cells. Tyrosol also promoted proteolytic cleavage of procaspase-3, -7, -8 and –9, increasing the amounts of cleaved caspase-3, -7, -8 and –9. In addition, tyrosol increased the levels of cleaved PARP in KB cells. These results suggest that tyrosol induces the suppression of cell growth and cell apoptosis in KB human oral cancer cells, and is therefore a potential candidate for anti-cancer drug discovery.

• Ue-Kyung Lee(Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea)
• Su-Gwan Kim(Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea)
• Dae-San Go(Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea)
• Sun-Kyoung Yu(Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea)
• Chun Sung Kim(Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea)
• Jeongsun Kim(Department of Dental Hygiene, Gwangju Health University, Gwangju 62287, Republic of Korea)
• Do Kyung Kim(Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 61452, Republic of Korea) Corresponding author